William Z. Foster: A cornerstone of the Communist class struggle policy is a ruthless fight against the Social Fascist leaders, especially those of the “left,” phrasemongering type. “Class Against Class” implies a war to the finish against such elements, who are part of the oppressive machinery of the capitalist class. They are enemies within the gates of the working class and must be treated as such. They head the labor movement only in order to behead it. They are a menace and an obstacle to all struggle by the workers. With their prestige as labor leaders, their demagogy is especially demoralizing; with their control of the workers’ mass organizations, they are able to effectively sabotage the struggle. It is idle to try to “convince” the Social Fascist leaders or to “force them to fight by mass pressure,” because they are class enemies of the workers. They must be politically obliterated. To accomplish this is a first condition for successful working class struggle and it is one never lost sight of by the Communist party. https://wordsmith.social/protestation/quotes#quote4749